庭院裡的水池

#include<bits/stdc++.h>
using namespace std;

//{
//#pragma gcc optimize("Ofast,unroll-loops")
//#pragma gcc target("sse,sse2,sse3,ssse3,sse4,avx,avx2,fma,abm,mmx,popcnt,tune=native")
//#define int long long
//#define double long double
#define MP make_pair
#define F first
#define S second
#define MOD 1000000007
//}

bool g[1002][1002], vis[1002][1002];
int dx[] = {-1, 1, 0, 0}, dy[] = {0, 0, -1, 1};

void dfs(int x, int y)
{
    vis[x][y] = true;
    for (int i = 0; i < 4; i++)
    {
        int nx = x + dx[i], ny = y + dy[i];
        if (!vis[nx][ny] && g[nx][ny])
            dfs(nx, ny);
    }
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int T;
    cin >> T;
    while (T--)
    {
        int N, M;
        cin >> N >> M;

        for (int i = 0; i <= N + 1; i++)
            for (int j = 0; j <= M + 1; j++)
                g[i][j] = false, vis[i][j] = false;

        for (int i = 1; i <= N; i++)
        {
            string s;
            cin >> s;

            for (int j = 1; j <= M; j++)
                if (s[j - 1] == '.')
                    g[i][j] = true;
        }

        int ans = 0;
        for (int i = 1; i <= N; i++)
            for (int j = 1; j <= M; j++)
                if (!vis[i][j] && g[i][j])
                    ans++, dfs(i, j);
        cout << ans << '\n';
    }

    return 0;
}

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